Cosmetic products are one of the most exciting application areas for microfibrillated cellulose (MFC). The opportunities within this field are almost endless as Mr. Rainer Kröpke from Cosmacon GmbH has learned when working with MFC in cosmetic applications. Mr. Kröpke has a long experience in formulating cosmetic products first at Beiersdorf (Germany) and since 2012 as a consultant. Read below his interview where he shares his experiences with all our blog readers.
Mr. Kröpke, have you formulated cosmetic products with MFC material?
Yes, I have prepared more than 250 different formulations with MFC. I think that MFC is a new, innovative raw material which is produced naturally and from sustainable forestry. I see much potential, especially when it comes to replacing synthetic raw materials.
What kind of formulations did you prepare using MFC?
I have formulated all sorts of emulsions with MFC; for example, oil in water (O/W) emulsions, water in oil (W/O) emulsions, gels, but also cream products, like aqueous lip balms. Also, I have tested MFC in various rinse-off formulations, like shampoos, conditioners and peeling products. In most of the cases, MFC brings a texturing effect in addition to the rheological properties, like stabilization or thickening.
How did you use MFC?
MFC is a multifunctional additive which can bring several benefits to various products. A distinct advantage of MFC is the rheological properties; it is a thickener and stabilizer. However, it can do a lot more than that in the cosmetic products. For example, in sunscreen sprays, MFC gives the “non-dripping” effect meaning that it prevents the dripping of the sunscreen product after being sprayed on the skin. MFC also reduces the common problem in sunscreen products, oiliness, and leaves behind a non-oily skin appearance.
Another interesting effect of MFC was that facial care products containing MFC displayed a soft focus effect. The three-dimensional structure of MFC helps to fill and shade away the tiny wrinkles, resulting in a matt, radiant finish.
MFC also suits to hair care products. The main benefit of MFC seen in hair care products is the conditioning effect, which improves the wet combability of hair. This effect can be measured particularly in the case of bristle, gray-white hair. A general advantage of using MFC is that it is salt-tolerant and can be used in formulations with a high amount of alcohol.
For rheology, did you substitute the rheology additive 1:1 with MFC?
Exactly, this is true when just replacing other rheology additives. For example, sodium magnesium silicates can be replaced 1:1 with MFC. However, when we are looking for other effects than just the rheology, it might be necessary to adjust the whole recipe. In shampoos, a number of of acrylate copolymers can be reduced when used together with MFC. MFC and the acrylates impact the rheology of the products, and MFC produces a conditioning effect on the hair. Sometimes, it might be optimal to use MFC in combination with another rheology additive. We have obtained good results in a 1:1 combination with microcrystalline cellulose or with a product containing cellulose gum, carrageenan, ceratonia siliqua gum and sucrose (Sucragel HC-31).
Which processing methods do you implement when using MFC? In which phase do you apply MFC?
There is no general answer to this question. It depends on the formulation and product type. Normally, MFC comes as a water suspension. I have mostly worked with 10% MFC paste but also sometimes with 2% MFC suspension. When manufacturing O/W formulations, the first option is to add MFC into the water phase before the emulsification step. MFC does not suffer from heating to 80 °C which is normally required for the emulsification step. If this does not work, I try to add MFC into the thickener phase. In this case, the oil and water phases are first combined and homogenized, cooled down to 40 °C, the thickener phase is added and homogenized again. A third option is to dilute MFC first in water and add as a separate phase after the emulsification step. In this case, I dilute 10% MFC 1:5 in water before adding into the formulation. Then follows the addition of the perfume and/or the active ingredients before a final homogenization.
I recommend to pay particular attention to the dispersion of MFC in water. MFC always needs high shear mixing to be well dispersed, emphasized with higher concentration MFC. It might be necessary to test few different dispersing methods to find the best solution.
How would you describe the processing of MFC compared to other rheology additives or soft focus additives?
As cosmetics developers, we are used to certain processes to introduce thickeners and/or pigments/soft focus pigments into the cosmetic formulations and find those processes normal. In some formulation types, MFC requires an adaptive modification of conventional manufacturing methods. However, it is worth investing some time to find the optimum conditions needed for MFC processing to work out the wonderful properties that MFC has. Sometimes MFC requires a special way to bring the three-dimensional structure into a new cosmetic formulation.
Finally, could you give us practical recommendations on how to formulate with MFC?
MFC is a new, innovative raw material for cosmetics. Sometimes this requires new ways of formulating. Consider one or more of the following suggestions:
- Try first to add MFC to the aqueous phase and process as usual.
- Add MFC 10% as a cold phase with water or MFC 2% as a separate raw material to the formulation before the first homogenization step.
- Should this fail to result in stable formulations, add MFC as a cold phase after the emulsification step and homogenize it in.
- In the case of rinse-off formulations, add it as the second-to-last phase and stir it in slowly, then neutralize or add perfume/active ingredient/salt phase.
We would like to thank Mr. Kröpke for sharing his experience with us!
Anni has worked with MFC since 2008, first at the Aalto University and the last two years at Borregaard as a research scientist. In her current work, she concentrates on the analysis of MFC and different technical applications. Her main interest lies in the flow properties and rheology of MFC. Anni has a doctoral degree in Polymer Technology.
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